Photonic switches, photonic switching fabrics and methods for data centers

Abstract

Data center interconnections, which encompass WSCs as well as traditional data centers, have become both a bottleneck and a cost/power issue for cloud computing providers, cloud service providers and the users of the cloud generally. Fiber optic technologies already play critical roles in data center operations and will increasingly in the future. The goal is to move data as fast as possible with the lowest latency with the lowest cost and the smallest space consumption on the server blade and throughout the network. Accordingly, it would be beneficial for new fiber optic interconnection architectures to address the traditional hierarchal time-division multiplexed (TDM) routing and interconnection and provide reduced latency, increased flexibility, lower cost, lower power consumption, and provide interconnections exploiting scalable optical modular optically switched interconnection network as well as temporospatial switching fabrics allowing switching speeds below the slowest switching element within the switching fabric.

What is claimed is: 
     
       1. An optical device comprising:
 an input portion attached to a substrate comprising a pair of optical input waveguides formed thereon; 
 an output portion attached to the substrate comprising a pair of optical output waveguides formed thereon; and 
 a suspended waveguide portion movable relative to the substrate coupled to a microelectromechanical systems (MEMS) actuator disposed between the input portion and the output portion comprising a set of optical waveguides where each optical waveguide of the set of optical waveguides has a first end disposed towards the input portion and a second distal end disposed towards the output portion; wherein 
 a first subset of the set of optical waveguides on the suspended waveguide portion run from the first end of the suspended waveguide portion to the second distal end of the suspended waveguide portion without crossing another optical waveguide of the set of optical waveguides on the suspended waveguide portion; 
 a second subset of the set of optical waveguides on the suspended waveguide portion run from the first end of the suspended waveguide portion to the second distal end of the suspended waveguide portion and each cross one or more other optical waveguides within the set of optical waveguides on the suspended waveguide portion; 
 the MEMS actuator in a first position positions the suspended waveguide portion such that it couples the pair of optical input waveguides to the pair of optical output waveguides placing the optical device into a first switch state; 
 the MEMS actuator in a second position positions the suspended waveguide portion such that it couples the pair of optical input waveguides to the pair of optical output waveguides placing the optical device into a second switch state. 
 
     
     
       2. The optical device according to  claim 1 , wherein
 the MEMS actuator may support a third position that positions the suspended waveguide portion so that it is neither in the first position or the second position such that optical signals from the pair of optical input waveguides are not coupled to the pair of optical output waveguides via any of the set of optical waveguides on the suspended waveguide portion. 
 
     
     
       3. The optical device according to  claim 1 , wherein
 the set of optical waveguides on the suspended waveguide portion comprises four optical waveguides;
 the first subset of the set of optical waveguides on the suspended waveguide portion is a single optical waveguide; and 
 the second subset of the set of optical waveguides on the suspended waveguide portion is three waveguides. 
 
 
     
     
       4. The optical device according to  claim 1 , wherein
 the first ends of each optical waveguide of the set of optical waveguides on the suspended waveguide portion are disposed laterally across the suspended waveguide portion; 
 the set of optical waveguides on the suspended waveguide portion comprises a first optical waveguide, a second optical waveguide, a third optical waveguide, and a fourth optical waveguide; 
 the first subset of the set of optical waveguides comprises the first optical waveguide; 
 the fourth optical waveguide crosses the third optical waveguide and the second optical waveguide such that the second distal end of the fourth optical waveguide is disposed adjacent to the second distal end of the first optical waveguide; 
 the third optical waveguide crosses the fourth optical waveguide and the second optical waveguide such that the second distal end of the third optical waveguide is disposed adjacent to the second distal end of the fourth optical waveguide on the opposite side to that of the second distal end of the first optical waveguide; and 
 the second optical waveguide crosses each of the third optical waveguide and the fourth optical waveguide such that the second distal end of the second optical waveguide is disposed adjacent to the second distal end of the third optical waveguide on the opposite side to that of the second distal end of the fourth optical waveguide. 
 
     
     
       5. The optical device according to  claim 1 , wherein
 the suspended waveguide portion may be latched when in at least one of the first position and the second position by one or more other MEMS actuators; and 
 the set of optical waveguides on the suspended waveguide portion optically couple to the pair of optical input waveguides and the pair of optical output waveguides via butt-coupling. 
 
     
     
       6. The optical device according to  claim 1 , wherein
 the suspended waveguide portion may be latched when in at least one of the first position and the second position by one or more other MEMS actuators; and 
 the set of optical waveguides on the suspended waveguide portion optically couple to the pair of optical input waveguides and the pair of optical output waveguides via one of lateral evanescent coupling and vertical evanescent coupling. 
 
     
     
       7. The optical device according to  claim 1 , further comprising
 one or more spring elements mechanically coupled at a first end to the substrate and at a second distal end to the suspended waveguide portion; and 
 one or more latches for latching the suspended waveguide portion into the first position; wherein 
 upon release of the one or more latches the suspended waveguide portion is moved into the second position through the action of the one or more spring elements; and 
 the MEMS actuator moves the suspended waveguide portion from the second position to the first position. 
 
     
     
       8. The optical device according to  claim 1 , further comprising
 one or more spring elements mechanically coupled at a first end to the substrate and at a second distal end to the suspended waveguide portion; and 
 one or more latches for latching the suspended waveguide portion into the second position; wherein 
 upon release of the one or more latches the suspended waveguide portion is moved into the first position through the action of the one or more spring elements; and 
 the MEMS actuator moves the suspended waveguide portion from the first position to the second position. 
 
     
     
       9. The optical device according to  claim 1 , further comprising
 one or more limiters attached to at least one of the input portion and the output portion; wherein 
 the one or more limiters limit movement of the suspended waveguide portion with respect to the input portion and the output portion. 
 
     
     
       10. An optical device comprising:
 a first non-suspended portion with a set of optical input waveguides formed thereon; 
 a second non-suspended portion with a set of optical output waveguides formed thereon; and 
 a suspended waveguide portion movable relative to the first non-suspended portion and the second non-suspended portion coupled to a set of microelectromechanical systems (MEMS) actuators with a set of optical waveguides formed thereon; wherein 
 the suspended waveguide portion is disposed between the first non-suspended portion and the second non-suspended portion; 
 each optical waveguide of the set of optical waveguides upon the suspended waveguide portion has a first end disposed towards the first non-suspended portion and a second distal end disposed towards the second non-suspended portion; 
 the MEMS actuator in a first position positions the suspended waveguide portion such that it couples a first predetermined subset of the set of optical input waveguides to a first predetermined subset of the set of optical output waveguides via a first predetermined subset of the set of optical waveguides upon the suspended waveguide portion thereby placing the optical device into a first switch state; 
 the MEMS actuator in a second position positions the suspended waveguide portion such that it couples a second predetermined subset of the set of optical input waveguides to a second predetermined subset of the set of optical output waveguides via a second predetermined subset of the set of optical waveguides upon the suspended waveguide portion thereby placing the optical device into a second switch state. 
 
     
     
       11. The optical device according to  claim 10 , wherein
 the MEMS actuator may support a third position that positions the suspended waveguide portion so that it is neither in the first position or the second position such that optical signals from the pair of optical input waveguides are not coupled to the pair of optical output waveguides via any of the set of optical waveguides on the suspended waveguide portion. 
 
     
     
       12. The optical device according to  claim 10 , wherein
 the set of optical waveguides on the suspended waveguide portion comprises four optical waveguides; 
 the first ends of each optical waveguide of the set of optical waveguides on the suspended waveguide portion are disposed laterally across the suspended waveguide portion; 
 the set of optical waveguides on the suspended waveguide portion comprises a first optical waveguide, a second optical waveguide, a third optical waveguide, and a fourth optical waveguide; 
 the first subset of the set of optical waveguides on the suspended waveguide portion comprises the first optical waveguide; 
 the second subset of the set of optical waveguides on the suspended waveguide portion comprises the second optical waveguide, the third optical waveguide and the fourth optical waveguide; 
 the fourth optical waveguide crosses the third optical waveguide and the second optical waveguide such that the second distal end of the fourth optical waveguide is disposed adjacent to the second distal end of the first optical waveguide; 
 the third optical waveguide crosses the fourth optical waveguide and the second optical waveguide such that the second distal end of the third optical waveguide is disposed adjacent to the second distal end of the fourth optical waveguide on the opposite side to that of the second distal end of the first optical waveguide; and 
 the second optical waveguide crosses each of the third optical waveguide and the fourth optical waveguide such that the second distal end of the second optical waveguide is disposed adjacent to the second distal end of the third optical waveguide on the opposite side to that of the second distal end of the fourth optical waveguide. 
 
     
     
       13. The optical device according to  claim 10 , wherein
 the suspended waveguide portion may be latched when in at least one of the first position and the second position by one or more other MEMS actuators; and 
 the set of optical waveguides on the suspended waveguide portion optically couple to the set of optical input waveguides and the set of optical output waveguides via butt-coupling. 
 
     
     
       14. The optical device according to  claim 10 , wherein
 the suspended waveguide portion may be latched when in at least one of the first position and the second position by one or more other MEMS actuators; and 
 the set of optical waveguides on the suspended waveguide portion optically couple to the set of optical input waveguides and the set of optical output waveguides via one of lateral evanescent coupling and vertical evanescent coupling. 
 
     
     
       15. The optical device according to  claim 10 , further comprising
 one or more spring elements mechanically coupled at a first end to the substrate and at a second distal end to the suspended waveguide portion; and 
 one or more latches for latching the suspended waveguide portion into the first position; wherein 
 upon release of the one or more latches the suspended waveguide portion is moved into the second position through the action of the one or more spring elements; and 
 the MEMS actuator moves the suspended waveguide portion from the second position to the first position. 
 
     
     
       16. The optical device according to  claim 10 , further comprising
 one or more spring elements mechanically coupled at a first end to the substrate and at a second distal end to the suspended waveguide portion; and 
 one or more latches for latching the suspended waveguide portion into the second position; wherein 
 upon release of the one or more latches the suspended waveguide portion is moved into the first position through the action of the one or more spring elements; and 
 the MEMS actuator moves the suspended waveguide portion from the first position to the second position. 
 
     
     
       17. The optical device according to  claim 10 , further comprising
 one or more limiters attached to at least one of the first non-suspended portion and the second non-suspended portion; wherein 
 the one or more limiters limit movement of the suspended waveguide portion with respect to the first non-suspended portion and the second non-suspended portion. 
 
     
     
       18. The optical device according to  claim 10 , wherein
 a first subset of the set of optical waveguides on the suspended waveguide portion run from a first end of the suspended waveguide portion to a second distal end of the suspended waveguide portion without crossing another optical waveguide of the set of optical waveguides on the suspended waveguide portion; and 
 a second subset of the set of optical waveguides on the suspended waveguide portion run from the first end of the suspended waveguide portion to the second distal end of the suspended waveguide portion and each cross one or more other waveguides of the set of optical waveguides of the suspended waveguide portion.